To date, electronic devices including electronic circuit boards are known. In electronic circuit boards, electronic elements, e.g., light emitting elements typified by LEDs (light emitting diodes) and thermoelements, are arranged.
An electronic circuit board in which an insulating layer is disposed on a metal substrate is known as an example of an electronic circuit board. For example, PTL 1 discloses a technology in which a base substrate is coated with a ceramic paint and firing is performed so as to form a coating film on the resulting base substrate.